Known methods for removing dirt and grime from eyeglass lenses, sunglass lenses, cellphone screens, watch crystals, TV or PC glass screens, mirrors, or other products include cleaning with a microfiber woven fabric, ultrasonic cleaning, or a cleaner containing a surfactant. Among these methods, cleaning with a cleaner containing a surfactant is simple and can be adapted to provide additional functions such as preventing readhesion of dirt and grime or preventing fogging on hard surfaces.
As an example of such cleaning with a cleaner containing a surfactant, Patent Literature 1 discloses a cleaner containing a fluorinated surfactant and a non-fluorinated surfactant. The cleaner, however, incorporates a comparatively large amount of the fluorinated surfactant in order to prevent readhesion of dirt and grime, and is not described as an anti-fogging agent. Indeed, the cleaner has an insufficient anti-fogging effect.
Patent Literature 2 discloses an anti-fogging cloth impregnated with a liquid containing a fluorinated cationic surfactant and a fluorinated nonionic surfactant. The anti-fogging cloth, however, is required to have a comparatively high fluorinated surfactant content, and hardly shows a long-lasting anti-fogging effect.